Manipulation-resistant combination lock



Dec. 25, 1956 F. J. BREMER MANIPULATION-RESISTANT COMBINATION LOCK 2 Sheets-Sheet. 1

Filed Dec. 29, 1950 mm mm CA MR Md WBM/ J 5 Dec. 25, 1956 F. J. BREMER MANIPULATION-RESISTANT COMBINATION LOCK 2 Sheets-Sheet 2 Filed Dec. 29, 1950 INVENTOR. FREDERICK d. BREMER United States Patent MANIPULATION-RESISTANT COMBINATION LOCK Frederick J. Brenner, Hamilton, Ohio, assignor to The Mosler Safe Company, Hamilton, Ohio, a corporation of New York Application December 29, 1950, Serial No. 203,431

11 Claims. (Cl. 70-133) This invention relates to combination locks and more particularly to improvements therein that render them resistant to unauthorized manipulation.

An object of this invention is to provide a combination lock having means for preventing telltale noises and vibrations which can be heard or felt while the tumblers are being manipulated, thereby making such locks substantially manipulation-proof.

Another object of the invention is to provide a combination lock with tumblers that are mounted for rotation on a spindle that is independent of the indexing spindle.

A further object of the invention is to provide a combination lock that is provided with an indexing spindle that is mounted for reciprocating motion into and out of driving relation with the tumblers.

A still further object of the invention is to provide a combination lock having tumblers provided with notches, the tumblers being rotatable on a spindle that is separate from the indexing spindle, a notched disk fast on the indexing spindle, and a lever having a lug and a bar disposed to seat in the tumbler and disk notches, respectively, when aligned with the bar and lug; to provide a lock having means whereby the bar and lug are held out of engagement with said notches at all times while the indexing spindle is being turned in accordance with the lock combination numbers; and to provide a lock in which the bar and lug are seated in the notches when aligned by shifting the indexing spindle along its axis to a position in which the driving connection between the indexing spindle and the tumblers is disengaged.

Other objects and features of the invention will in part be apparent and will in part be obvious from the following description taken in conjunction with the accompanying drawings in which:

Figure 1 is a view in side elevation and partly in vertical section taken on line I-I of Fig. 3, of a lock embodying a form of the invention, the indexing spindle being shown in a position in which the tumblers can be turned thereby, the tumblers being in a position in which the notches are out of alignment;

Fig. 2 is a View similar to Fig. l, in section, taken on line lIII of Fig. 4, the tumblers being shown in alignment so that the lock may be opened or closed;

Figs. 3, 4 and 5 are rear views of the lock with the tumblers removed, showing the positions of lug lever and bar relative to the indexing spindle when the lock is locked, and the motions of the spindle and bolt as the bolt is actuated from locked to unlocked position;

Fig. 6 is a partial view in section taken on line VI-Vl of Fig. 5;

Fig. 7 is a view in front elevation of a tumbler embodied in the lock shown by the preceding views;

Fig. 8 is a view in section taken on line VllIVlIl of Fig. 7; and

Figs. 9 and 10 are views of one face and the edge, respectively, of a modified form of disk tumbler that may be used in the lock shown in the preceding views.

" ice In Figs. 1 and 2 of the drawings, a combination lock 1 is illustrated as mounted on a door 2 of a safe or other compartment, not shown. The lock comprises a plurality of circular tumblers 3, 4 and 5 rotatably mounted on a stationary spindle 6, and an indexing spindle 7 that extends through the door, the spindle 7 being provided with a disk 8 that is rigidly secured to the inner end thereof. The lock includes also a sliding bolt 10 and a lever 11 pivotally mounted on a pin 12 secured to the bolt. Lever 11 is provided with a bar 13 that extends across the tumblers, the bar being substantially perpendicular to the lever. Lever 11 is urged towards disk 8 and tumblers 3, 4 and 5 by a spring 14, one end of which is coiled about and anchored to pin 12, and the other of which overhangs the lever as shown, thereby urging the lever counter-clockwise about the pin as seen in Figs. 3-5 inclusive.

As shown more particularly in Figs. 2 and 8, spindle 6 is hollow and stationary, being secured to and supported by a cover plate 15 of a housing 16 which is fastened to the inside face of a door 2. The tumblers are freely rotatable on spindle 6 and are spaced from each other and the cover plate 15 by means of washers 17 that minimize friction between them. The tumblers are held in place on the spindle by means of a split ring 18 which is retained in a groove 19 at the free end of. the spindle.

Each tumbler 3, 4 and 5 is provided with a notch 20 in its periphery. When the notches 243 are in alignment, bar 13 may be received in the notches preparatory to opening or closing the look, as will be explained infra.

The tumblers 3, 4 and 5 are substantially similar in construction and may be constructed as shown in Figs. 7 and 8. As there illustrated, each tumbler comprises an outer ring or annulus 22 and a center plug or disk 23. The periphery of disk 23 and the adjacent surface of the opening in the annulus 22 may be provided with registering teeth 24. The diameters of the disk and the opening in the annulus are such that the disk has a press fit with the teeth, as shown. The annulus may be provided with graduations 25 around the opening therein whereby the combination of the lock may be pre-set or changed from time to time, as desired. Key change tumblers may be employed if desired.

The center disk or plug 23 is provided on one face thereof with an annular groove 27 that is concentric with the axis of rotation of the tumbler. The center disk is also provided with a notch 28 that extends over a predetermined part of the periphery thereof, as for example, approximately 15 divisions or 15% of the total periphery. In the slot 27 is a ring 29 that turns freely therein. The ring is provided with a tab 36 that extends into notch 28, as shown. Ring 29 may therefore be: turned in the slot or groove 27 until the tab 30 abuts against one end or the other of notch 28. On the opposite face of disk or plug 23 is a pin 32. Pin 32 is so positioned that it will run in the groove 27 of an adjacent tumbler. If a tumbler is turned with respect to an adjacent tumbler, pin 32 will engage one side or the other of tab 3 0 and turn it until it strikes one end or the other of notch 28, whereupon further turning of the tumbler will cause the adjacent tumbler to turn with it. As there is no need for a pin 32 on tumbler 3, none is shown thereon in the drawings.

The indexing spindle 7 as shown in Fig. 2, is provided at its outer end with an index plate 37 that operates in a recess 39 in a stationary dial plate or ring 40 which is secured to the door. The stationary ring 40 and the index plate 37 are provided with indicia or graduations running from, say, zero to 100, whereby the lock may be indexed in accordance with the combination thereof, as is well understood in this art. The indexing spindle is rotatable about an axis that is co-axial with the axis of the stationary tumbler spindle 6. It is also movable along its longitudinal axis into and out of the recess 39, for a purpose that will be described infra.

The inner end of spindle 7 is threaded and disk 8 is threaded onto the same. The spindle and disk are locked together by a key 41, the key slots in the disk and spindle being so located that a predetermined point on the disk will always be in a fixed position relative to the zero on the index plate 37.

Disk 8 comprises essentially two disks or disk sections 42 and 43. The diameter of disk 42 is less than the diameters of the tumblers 3, 4 and 5, and the diameter of disk 43 is greater than the diameters of the tumblers. The inner edge of said disk 43 is rounded as at 43 as shown. When spindle 7 and disk 43 are pushed inwardly fromthe position shown in Fig. 2 tothe Fig. 1 position the rounded edge 43' acts on the adjacent lower corner of lug 11' to raise it upwardly and at the same time raise the lever 11 and the fence or bar 13. The indexing spindle and its disk 8 are urged inwardly towards the tumblers by means of a spring 44. When in the position shown in Fig. 1, a lug 11 at the free end of lever 11 rides on the periphery of disk 43. The position of disks 42 and 43, as shown in Fig. 1, is the normal position of the disks when the lock is being indexed in accordance with its combination. The inner disk 42 is provided with a notch 47 into which lug 11 at the free end of lever 11 may drop, provided the notches in the tumblers are in alignment with each other and with notch 47 and the indexing spindle is pulled outwardly to the position shown in Fig. 2. i

The inner face of disk 42 is provided with a pin 50 disposed to run in the groove 27 of tumbler 5. This pin forms the driving connection between the indexing spindle and the tumblers. The pin 32 on each of tumblers and 4, the rings 29and their tabs 30 in conjunction with the notches 28 form the driving connections between the respective tumblers 3, 4 and 5. The form of bolt may be such as is suited to the particular type of lock to be constructed. As illustrated, the bolt comprises a forklike plate 51 that straddles the inner end of the indexing spindle 7 and slides along the housing side wall as shown, and a short bar-like portion 52 that is adapted to move into or out of the bolt keeper of the door. The bolt portion 51 has an oifset portion 53 to which the lever 11 is secured.

The top of housing 16 is provided with a depending lug'55 which prevents lever 11 from turning clockwise and disengaging bar 13 and lug 11 from the tumbler notches and disk notch 47 when the tumblers and lock bolt are being moved to or from the positions indicated in Figs. 5 and 4, respectively. The end 56 of lever 11 adjacent edge 57 of lug 55, is fiat and substantially parallel to a vertical plane passing through the axis of spindle 7. Edge 57 of lug 55 is inclined at a slight angle to end 56 so that it will clear the lug when the lever turns counterclockwise from the Fig. 3 to the Fig. 4 position. By shaping the end of lever 11 and the edge 57 of lug 55 as stated, neither endwise nor downward pressure on bolt 52 will cause lever 11 to turn in a direction to cause bar 13 to engage the tumblers or the lever to engage notch 47 while such pressure is applied to the bolt and the spindle 7 and disk 8 are in the position shown in Fig. 2 while such pressure is applied. This feature adds to the resistance qualities of the lock against unauthorized manipulation. As can be seen in Fig. 3, inward endwise or downward pressure on bolt 52 will force the end show, the bar 13 and lever 11 do not make any contact with the notch in disk .42 and the tumblers while the lock is being indexed by the, indexing spindle. The turn blers can not be turned except when pin of the indexing spindle is in driving relation with tumbler 5. The driving relation is established when the indexing spindle is in the position shown in Fig. 1. j

When the driving connection between the indexing spindle and the tumblers is effected, it will be seen in Figs. 1 and 3 that lever lug 11' rides on the periphery of disk 43. As this periphery is smooth, no clicking noise can be heard, neither can any click be felt by sensitive fingers as the indexing spindle is turned.

If it be assumed that the sequence of tumbler notch alignment is that the notches of tumblers 3, 4 and 5 are aligned with bar 13 in that sequence, then the first step in opening the lock is the turning of dial plate 37 to a position where its zero is opposite the zero ofthe dial ing 40. Then in accordance with the combination of the lock, the indexing spindle is turned a predetermined number of graduations in one direction to align the notch in tumbler 3 with bar 13. The spindle is then turned in the opposite direction two complete revolutions to a particular position on the dial whereby the notch of tumbler 4 is aligned with bar 13 and with the notch in tumbler 3. The indexing spindle is then turned in the opposite direction in accordance with the lock combination until the notch in tumbler 5 is in alignment with of lever 11 firmly against lug 55 and prevent turning of the lever in a counterclockwise direction as there will be no downwardly acting vertical component of the pressure exerted on the lever to turn it. Since the lever engages lug 55 under such circumstances the lever is locked and cannot be turned by the spring 14 towards disk 43.

V The lock constructionabove described is manipulation resistant, because, as the following description will the notches of tumblers 3 and 4 and with bar 13. At this point the driving connection between the indexing spindle and the tumblers is disengaged by pulling the spindle outwardly to the position shown in Fig. 2. While the spindle is thus disengaged, the spindle is turned to zero at which point the notch in disk 42 will be aligned with the notches in the tumblers and with bar 13. When so aligned, bar 13 drops into the notches of the tumblers and the lug 11 at the end of lever 11 drops into the notch on disk 42.

When bar 13 and lever lug 11 are in the notches as just described, the lock may be opened by turning the spindle in the opening direction. The bolt or bar portion 52 will then be in the position shown in Fig. 5. By turning the spindle in the opposite direction, the bolt bar 52 is moved to the locked position, as shown in Fig. 4.

- After the lock bolt 52 has been actuated to the Fig. 4

position lever 11 may be raised to the position shown in Fig. 3 by pushing spindle 7 and disk 8 inwardly to the Fig. 1 position. As the disk approaches the Fig. l position the rounded edge 43' engages the adjacent bottom corner of lug 11' thereby raising lever 11 and bar 13 to the position where the rim of disk section 43 will be under lug 11' of lever 11 as shown in Fig. 3. As shown in Fig. 4 the trailing edge of notch 47 raises lever 11 as the indexing spindle 7 is continued to be turned in that direction which actuates bolt 52 to the Fig. 4 position. When so raised by the trailing edge of notch 47 the shifting of the index spindle and disk 43 to the Fig. 1 position raises the lever 11 and bar 13 to the positions shown by Figs. 1 and 3.

If an unauthorized person attempts to manipulate the lock, it will be seen that no clicking noise can be heard nor can any tumbler notch clicks be felt while the lock indexing spindle is being turned. If the indexing spindle is in the position shown in Fig. 1, bar 13 is held out of engagement with the tumbler disks because lever 11 rides on the smooth surfaced disk 33. If the indexing spindle is turned while in the position shown in Fig. 1, and the tumbler notches are out of alignment with the notch in disk 42, it will be apparent that if the indexing spindle is pulled outwardly to the position shown in Fig. 2, the bar will ride on the periphery of the tumblers so that the bar can not engage any notch thereof; neither can lever lug 11' engage or make contact with the notch in disk 42 because the diameters of the tumblers are larger than the diameter of disk 42 and pin 50 is disengaged restricting movement of tumblers.

The modern technique of opening combination locks without authority, is to use electronic devices which pick up the faintest noises in a lock as it is manipulated. Ex- I perts can use information obtained by such devices to a large number of fine closely spaced teeth 58 on the peripheries thereof, as shown in Figs. 9 and 10. The sounds and vibrations produced by these teeth when lever lug 11 and bar 13 make contact therewith as when spindle 7 is pulled outwardly, will serve to develop sounds or vibrations. Those vibrations or sounds tend to conceal the location of the tumbler notches, and make it still more dilficult to ascertain the lock combination.

From the foregoing description, it will be apparent that the combination lock embodying this invention is manipulation resistant because no tell-tale clicks can be heard or felt as the locks indexing spindle is turned. The lock can be opened only by following the instructions of the combination.

Having thus described the invention, it will be apparent to those skilled in this art that various modifications and changes may be made in the illustrated embodiment thereof without departing from either the spirit or the scope of the invention.

Therefore, what is claimed as new and desired to be secured by Letters Patent is:

. 1. A combination lock comprising a support having a spindle, a reciprocable bolt, a plurality of circular tumblers rotatably mounted on the spindle, each of said tumblers having a notch in the periphery thereof, a rotatable lock indexing and driving spindle having its axis of rotation coaxial with the axis of the tumbler spindle, said driving spindle being movable along its axis of rotation and having adisk thereon, the inner portion of which is of lesser diameter than the outer portion thereof, the outermost portion of said disk being of a greater diameter than the diameters of said tumblers and the inner portion of said disk being provided with a notch, a bar pivotally mounted on said bolt, said bar extending transversely of said tumblers and disk and being provided with a cam disposed to normally engage the outer portion of said disk and hold the bar out of contact with the rims of said tumblers, said tumblers being coupled to each other with lost motion driving connections and said spindle disk having a lost motion driving connection with one of said tumblers when the spindle disk is in one position, said spindle disk being disengaged therefrom when actuated away from said tumblers, said tumblers being actuated in sequence to a position in which said notches line up with said bar and the notch in the spindle disk by turning said indexing spindle in accordance with the lock combination, said bar dropping into said notches by moving said indexing spindle in a direction in which the disk thereof is moved away from the adjacent tumbler.

2. A combination lock comprising a plurality of rotatable circular disk tumblers having lost motion driving connections one with another, each tumbler having a notch in its periphery, an indexing and driving spindle coaxial with said tumblers and having a disk mounted parallel with and adjacent to one of said tumblers, said spindle being movable along its axis of rotation in either direction towards or away from its adjacent tumbler, said spindle disk having a lost motion driving connection with its adjacent tumbler when the spindle is in one of said positions, said lost motion driving connection being disengaged when the spindle is in the other of said positions, said disk having an outer section whose diameter is greater than that of the tumblers and a section adjacent one of said tumblers whose diameter is less than that of the tumblers, said inner section having a notch in the periphery thereof, a lock bolt, a lever pivotally mounted on said bolt and having a bar extending across said tumblers in a direction parallel to the axis of rotation of the tumblers and disk, said lever normally riding on the portion of the disk of larger diameter when the notches of the disk and tumblers are out of register, the bar resting on said tumblers and holding the lever out of engagement with said disk notch when the disk is out of driving engagement with its adjacent tumbler, the notches in said tumblers and disk being aligned by indexing the spindle in accordance with the lock combination when the driving connection is established, the bar dropping into said notches when the spindle and spindle disk are actuated to disengage the lost motion driving connection with the adjacent tumbler, whereby the lock bolt may be actuated by turning the spindle.

3. A combination lock having a sliding bolt, an indexing spindle having a disk thereon provided with a notch in the periphery thereof, a pivotally mounted lever connected to and movable with the bolt as the bolt is reciprocated thereby when the lever is in said notch, said spindle being slidable along its longitudinal axis from a position in which the lever may be received in said notch to a position in which the lever can not be seated therein, a plurality of notched circular tumblers mounted to rotate about a common axis that is co-axial with the spindle axis, said tumblers having a lost motion driving connection one with another, said spindle disk having a circular portion of larger diameter than the notched portion of the spindle disk upon which said lever rides when the spindle is in one position, the diameters of said tumblers being larger than the notched portion of the spindle disk and smaller in diameter than the circular portion of larger diameter, said spindle disk having a driving connection with its adjacent tumbler when in the position in which said lever rides on the circular portion of said disk, and a bar extending from said lever across said tumblers, said bar resting thereon when the notches are not in alignment and holding the lever out of said disk notch when the spindle is in a position to be disconnected from said tumbler, said tumblers being rotatable to align the notches when the spindle is turned in accordance with the combination of the lock when the driving connection is established, the bar and lever dropping into said tumbler notches and spindle disk notch, respectively, when the spindle disk notch is aligned with said tumbler notches and the spindle disk is moved to a position where the adjacent tumbler is disengaged therefrom, whereby the lock bolt may be moved to or from locked position by turning said spindle.

4. A combination lock comprising a rotatable and longitudinally reciprocable indexing spindle, a tumblersupporting spindle, the major axes of said spindles being in alignment, a plurality of tumbler disks rotatably mounted on said tumbler-supporting spindle as a group, each tumbler having a radical notch in its periphery, means providing lost motion driving connections between the respective tumbler disks, a disk mounted on and secured to the indexing spindle at a location adjacent one of said tumbler disks, means providing a lost motion driving connection between said indexing spindle and one of said tumbler disks, said spindle disk having a section whose diameter is greater than the diameter of the tumbler disks and a section between said group of tumbler disks and said first mentioned section whose diameter is less than the diameters of the tumbler disks, said latter disk section having a radial notch therein, a reciprocable lock bolt, a lever pivotally mounted on said bolt having a bar extending across said tumbler disks and a lug shaped to fit in said spindle disk notch, said lug riding on the spindle disk of larger diameter when the indexing spindle is in driving engagement with said tumbler disks and said bar resting on the periphery of said tumbler disks when the driving connection between said indexing spindle and tumbler disks is disengaged whereby clicking or feeling of the tumbler and spindle disk notches with the lever lug and bar is prevented, said tumbler .disk notches being aligned with said bar by rotating the tumbler disks by means of the indexing spindle when the driving connection is established, said bar and lever lug dropping into said notches when the indexing spindle has been indexed to unlocking position and the indexing spindle-tumbler disk driving connection has been disengaged, the lock bolt being reciprocable to and from locking position by said spindle through the driving connection formed by the lever lug and said spindle disk notch.

5. A lock according toclaim 4 characterized by the fact that the tumbler-supporting spindle is hollow and that the one end of the indexing spindle is slidably disposed in the hollow of said tumbler-supporting spindle.

6. A lock according to claim 4 characterized by the fact that the tumbler-supporting spindle is hollow, that one end of the indexing spindle is slidably disposed in the hollow of said tumbler-supporting spindle, and that means are provided for yieldingly urging the indexing spindle in a direction to effect engagement of the driving connection between it and the tumbler disks.

7. A lock according to claim 4 characterized by the fact that lost motion driving connection between the tumbler disks is formed by providing the tumbler disks with arcuate slots having spaced abutments and providing each tumbler disk save one, with a pin that is disposed to run in the slots of an adjacent tumbler disk to operatively engage one or the other of said abutments, and that the indexing spindle disk is provided with a pin disposed to run in the slot of the immediately adjacent tumbler disk and have operative engagement with one or the other of said abutments therein.

8. A lock according to claim 4 characterized by the fact that the lost motion driving connection between tumbler disks comprises spaced abutments on the corresponding face of each tumbler disk, the abutments being equidistant from the center of rotation of the tumbler disks, a pin secured to the opposite faces of the tumbler disks which lie adjacent said abutments, and disposed to have operative engagement with one or the other of said abutments and turn the tumbler disk thereof, and a drive pin on the indexing spindle disk disposed to have operative engagement with one or the other of the abutments in the adjacent tumbler disk.

9. A lock according to claim 4 characterized by the fact that each tumbler disk comprises an annulus and a plug within the annulus, said plug being adjustably secured to the annulus, the plug having on one face spaced abutments located equi-distant from the center of rotation of the tumbler disk and on the opposite face a pin disposed to have operative engagement with one or the other of the abutments on the adjacent face of an adjacent tumbler disk.

10. A lock according to claim 4, characterized by the fact that the peripheries of the tumbler disks are provided '8 with closely spaced teeth jupon which said bar restswhen the spindle is moved to a position where the driving connection between the spindle disk and the adjacent tumbler diskis disengaged. M

- 11. .A combination lock comprising a support, a bolt slidably mounted on said support, a dialshaft movably carried by said support and having a disk thereon provided with a gate in the periphery thereof, a fence lever having fence. means including a disk follower nose and being pivotally mounted on and movable with said bolt as the bolt is reciprocated thereby when the disk follower nose is in said gate, said shaft being slidable along its longitudinal axis from a position in which said disk follower nose may be received in said gate to a position in which said disk follower nose can not be received therein, a spindle fixed to said support in coaxial relation to said shaft, a plurality of cylindrical tumblers rotatably mounted on said spindle, said tumblers each having a gate in the periphery thereof, said tumblers having a lost motion driving connection one with another, said disk having a circular portion of larger diameter than the gated portion thereof upon which said disk follower nose rides when the shaft is in one position, said disk having a driving connection with its adjacent tumbler when in the position in which said disk follower nose rides on the circular portion of said disk, and said fence means also including a bar extending from said fence lever across said tumblers, said circular portion of larger diameter of said disk being of such diameter as to hold the barout of contact with the rims of said tumblers when said disk is in a position to be connected with said adjacent tumbler and said notched portion of said disk being of such diameter that said bar will'rest on'the peripheries of said tumblers and hold the disk follower nose out of said disk gate when the gates of the tumblers are not in alignment and when said disk is in a position to be disconnected from said adjacent tumbler, said tumblers being rotatable to align their gates with said bar when said shaft is turned in accordance with the combination of the lock when the driving connection is established, said bar and disk follower nose dropping into said tumbler gates and disk gate, respectively, when the disk gate is aligned with said tumbler gates and the disk is moved to .a'position where the adjacent tumbler is disengaged therefrom, whereby the lock bolt may be moved to or from locked position by turning said shaft.

References Cited in the file of this patent UNITED STATES PATENTS 2,575,674 Miller Nov. 20, 1951 

